right now i have 9800gt..should i switch to ati cards???
Switching to ATI would probably be based on your power supply. The modern AMD cards run on much less power while maintaining comparable performance.
The 560 has a TDP of 160W, while a 7850 has a TDP of 130W. A 9800GT looks to be either 105 or 125W.
A nice card with similar TDP to your 9800GT would be a AMD 6850 and it might meet your price requirements and give a great upgrade.